Supreme Court rules on emissions case

EPA may require businesses to install modern air pollution control equipment if renovations to a facility cause its emissions to rise on an annual basis, the U.S. Supreme Court ruled unanimously on April 2. The decision is expected to influence whether companies, including electric utilities and chemical manufacturing plants, will have to install expensive emission controls on older facilities. The case involves part of the Clean Air Act called new source review. This provision requires industry to put in place up-to-date air pollution controls when modifications to a facility cause emissions to rise. The suit revolved around just what constitutes an increase in emissions. The high court rejected utility Duke Energy's reasoning, which had been endorsed by a federal circuit court, that EPA should determine pollution increases by examining a plant's hourly emissions before and after a modification.